FAQ.How to check whether a folderitem is in the LoginItems?
Feedback.

Answer: The following code may help to check for a folderitem in the login items:
Example:

Function isFolderItemInLoginItems(item as folderitem) As boolean
  dim c as integer
  dim s as string
  dim i as integer
  dim u as CFURLMBS
  dim path as string
  
  u=NewCFURLMBSFile(item)
  
  path=u.PosixFileSystemPath.str
  
  c=CountOfLoginItemsMBS(false)
  for i=1 to c
    s=LoginItemPropertyAtIndexMBS(1,i,false)
    
    if s=path then
      Return true
    end if
  next
  
  Exception e
  Return false
End Function

// An example on how to use it:

dim f as FolderItem

f=ApplicationsFolderMBS(0).Child("iChat.app")

if isFolderItemInLoginItems(f) then
  MsgBox "iChat is in the Login items."
else
  MsgBox "iChat is not in the Login items."
end if

Notes:
This will not work with pathes relative to the user's local folder.
You may better add a second check for the application name as there may already be another version of your application being registered.